Surgical instrument with automatically-returned firing member

ABSTRACT

A surgical instrument is disclosed. The surgical instrument comprises a handle, a shaft comprising a proximal portion extending from the handle and a distal portion, and a firing member. The surgical instrument further comprises a motor, wherein the motor is configured to be operated in a first direction to advance the firing member toward the distal portion during a firing stroke, wherein the firing stroke comprises a firing stroke end, and wherein the motor is configured to be operated in a second direction to retract the firing member away from the distal portion. The surgical instrument further comprises a switch configured to detect when the firing member has reached the firing stroke end, wherein the motor is configured to be automatically operated in the second direction when the switch detects the firing stroke end.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application under 35 U.S.C.§120 of U.S. patent application Ser. No. 13/791,909, filed Mar. 9, 2013,entitled SURGICAL INSTRUMENT, now U.S. Patent Publication No.2013/0186933, which is a continuation application under 35 U.S.C. §120of U.S. patent application Ser. No. 13/627,241, filed Sep. 26, 2012,entitled SURGICAL INSTRUMENT, now U.S. Patent Publication No.2013/0020375, which is a continuation application under 35 U.S.C. §120of U.S. patent application Ser. No. 13/424,648, filed on Mar. 20, 2012,entitled SURGICAL INSTRUMENT HAVING RECORDING CAPABILITIES, now U.S.Pat. No. 8,752,747, which is a divisional application under 35 U.S.C.§121 of U.S. patent application Ser. No. 12/949,099, filed on Nov. 18,2010, entitled SURGICAL INSTRUMENT HAVING RECORDING CAPABILITIES, whichissued as U.S. Pat. No. 8,167,185 on May 1, 2012, which is acontinuation application under 35 U.S.C. §120 of U.S. patent applicationSer. No. 11/343,803, filed on Jan. 31, 2006, entitled SURGICALINSTRUMENT HAVING RECORDING CAPABILITIES, which issued as U.S. Pat. No.7,845,537 on Dec. 7, 2010, the disclosures of which are incorporatedherein by reference in their entireties.

The present application is related to the following U.S. patentapplications, which were concurrently filed on Jan. 31, 2006, which areincorporated herein by reference:

-   U.S. patent application Ser. No. 11/343,498, now U.S. Pat. No.    7,766,210, entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING    INSTRUMENT WITH USER FEEDBACK SYSTEM; Inventors: Frederick E.    Shelton, IV, John Ouwerkerk and Jerome R. Morgan-   U.S. patent application Ser. No. 11/343,573, now U.S. Pat. No.    7,416,101, entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING    INSTRUMENT WITH LOADING FORCE FEEDBACK; Inventors: Frederick E.    Shelton, IV, John N. Ouwerkerk, Jerome R. Morgan, and Jeffrey S.    Swayze-   U.S. patent application Ser. No. 11/344,035, now U.S. Pat. No.    7,422,139, entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING    INSTRUMENT WITH TACTILE POSITION FEEDBACK; Inventors: Frederick E.    Shelton, IV, John N. Ouwerkerk, Jerome R. Morgan, and Jeffrey S.    Swayze-   U.S. patent application Ser. No. 11/343,447, now U.S. Pat. No.    7,770,775, entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING    INSTRUMENT WITH ADAPTIVE USER FEEDBACK; Inventors: Frederick E.    Shelton, IV, John N. Ouwerkerk, and Jerome R. Morgan-   U.S. patent application Ser. No. 11/343,562, now U.S. Pat. No.    7,568,603, entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING    INSTRUMENT WITH ARTICULATABLE END EFFECTOR; Inventors: Frederick E.    Shelton, IV and Christoph L. Gillum-   U.S. patent application Ser. No. 11/344,024, now U.S. Pat. No.    8,186,555, entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENING    INSTRUMENT WITH MECHANICAL CLOSURE SYSTEM; Inventors: Frederick E.    Shelton, IV and Christoph L. Gillum-   U.S. patent application Ser. No. 11/343,321, now U.S. Patent    Publication No. 2007/0175955, entitled SURGICAL CUTTING AND    FASTENING INSTRUMENT WITH CLOSURE TRIGGER LOCKING MECHANISM;    Inventors: Frederick E. Shelton, IV and Kevin R. Doll-   U.S. patent application Ser. No. 11/343,563, now U.S. Patent    Publication No. 2007/0175951, entitled GEARING SELECTOR FOR A    POWERED SURGICAL CUTTING AND FASTENING STAPLING INSTRUMENT;    Inventors: Frederick E. Shelton, IV, Jeffrey S. Swayze, Eugene L.    Timperman-   U.S. patent application Ser. No. 11/344,020, now U.S. Pat. No.    7,464,846, entitled SURGICAL INSTRUMENT HAVING A REMOVABLE BATTERY    Inventors: Frederick E. Shelton, IV, Kevin R. Doll, Jeffrey S.    Swayze and Eugene Timperman-   U.S. patent application Ser. No. 11/343,439, now U.S. Pat. No.    7,644,848, entitled ELECTRONIC LOCKOUTS AND SURGICAL INSTRUMENT    INCLUDING SAME; Inventors: Jeffrey S. Swayze, Frederick E. Shelton,    IV, Kevin R. Doll-   U.S. patent application Ser. No. 11/343,547, now U.S. Pat. No.    7,753,904, entitled ENDOSCOPIC SURGICAL INSTRUMENT WITH A HANDLE    THAT CAN ARTICULATE WITH RESPECT TO THE SHAFT; Inventors:    Frederick E. Shelton, IV, Jeffrey S. Swayze, Mark S. Ortiz, and    Leslie M. Fugikawa-   U.S. patent application Ser. No. 11/344,021, now U.S. Pat. No.    7,464,849, entitled ELECTRO-MECHANICAL SURGICAL CUTTING AND    FASTENING INSTRUMENT HAVING A ROTARY FIRING AND CLOSURE SYSTEM WITH    PARALLEL CLOSURE AND ANVIL ALIGNMENT COMPONENTS; Inventors:    Frederick E. Shelton, IV, Stephen J. Balek and Eugene L. Timperman-   U.S. patent application Ser. No. 11/343,546, now U.S. Patent    Publication No. 2007/0175950, entitled DISPOSABLE STAPLE CARTRIDGE    HAVING AN ANVIL WITH TISSUE LOCATOR FOR USE WITH A SURGICAL CUTTING    AND FASTENING INSTRUMENT AND MODULAR END EFFECTOR SYSTEM THEREFOR;    Inventors: Frederick E. Shelton, IV, Michael S. Cropper, Joshua M.    Broehl, Ryan S. Crisp, Jamison J. Float, Eugene L. Timperman-   U.S. patent application Ser. No. 11/343,545, now U.S. Patent    Publication No. 2007/0175949, entitled SURGICAL INSTRUMENT HAVING A    FEEDBACK SYSTEM; Inventors: Frederick E. Shelton, IV, Jerome R.    Morgan, Kevin R. Doll, Jeffrey S. Swayze and Eugene Timperman

BACKGROUND

The present invention relates in general to surgical instruments, andmore particularly to minimally invasive surgical instruments capable ofrecording various conditions of the instrument.

Endoscopic surgical instruments are often preferred over traditionalopen surgical devices because a smaller incision tends to reduce thepost-operative recovery time and complications. Consequently,significant development has gone into a range of endoscopic surgicalinstruments that are suitable for precise placement of a distal endeffector at a desired surgical site through a cannula of a trocar. Thesedistal end effectors engage the tissue in a number of ways to achieve adiagnostic or therapeutic effect (e.g., endocutter, grasper, cutter,staplers, clip applier, access device, drug/gene therapy deliverydevice, and energy device using ultrasound, RF, laser, etc.).

Known surgical staplers include an end effector that simultaneouslymakes a longitudinal incision in tissue and applies lines of staples onopposing sides of the incision. The end effector includes a pair ofcooperating jaw members that, if the instrument is intended forendoscopic or laparoscopic applications, are capable of passing througha cannula passageway. One of the jaw members receives a staple cartridgehaving at least two laterally spaced rows of staples. The other jawmember defines an anvil having staple-forming pockets aligned with therows of staples in the cartridge. The instrument includes a plurality ofreciprocating wedges which, when driven distally, pass through openingsin the staple cartridge and engage drivers supporting the staples toeffect the firing of the staples toward the anvil.

An example of a surgical stapler suitable for endoscopic applications isdescribed in U.S. Pat. No. 5,465,895, entitled “SURGICAL STAPLERINSTRUMENT” to Knodel et al., which discloses an endocutter withdistinct closing and firing actions. A clinician using this device isable to close the jaw members upon tissue to position the tissue priorto firing. Once the clinician has determined that the jaw members areproperly gripping tissue, the clinician can then fire the surgicalstapler with a single firing stroke, or multiple firing strokes,depending on the device. Firing the surgical stapler causes severing andstapling of the tissue. The simultaneous severing and stapling avoidscomplications that may arise when performing such actions sequentiallywith different surgical tools that respectively only sever and staple.

One specific advantage of being able to close upon tissue before firingis that the clinician is able to verify via an endoscope that thedesired location for the cut has been achieved, including a sufficientamount of tissue has been captured between opposing jaws. Otherwise,opposing jaws may be drawn too close together, especially pinching attheir distal ends, and thus not effectively forming closed staples inthe severed tissue. At the other extreme, an excessive amount of clampedtissue may cause binding and an incomplete firing.

When endoscopic surgical instruments fail, they are often returned tothe manufacturer, or other entity, for analysis of the failure. If thefailure resulted in a critical class of defect in the instrument, it isnecessary for the manufacturer to determine the cause of the failure anddetermine whether a design change is required. In that case, themanufacturer may spend many hundreds of man-hours analyzing a failedinstrument and attempting to reconstruct the conditions under which itfailed based only on the damage to the instrument. It can be expensiveand very challenging to analyze instrument failures in this way. Also,many of these analyses simply conclude that the failure was due toimproper use of the instrument.

SUMMARY

In various embodiments, a surgical instrument is disclosed. The surgicalinstrument comprises a handle, a shaft comprising a proximal portionextending from the handle, and a distal portion. The surgical instrumentfurther comprises a firing member, a motor, wherein the motor isconfigured to be operated in a first direction to advance the firingmember toward the distal portion during a firing stroke, wherein thefiring stroke comprises a firing stroke end, and wherein the motor isconfigured to be operated in a second direction to retract the firingmember away from the distal portion, and a switch configured to detectwhen the firing member has reached the firing stroke end, wherein themotor is configured to be automatically operated in the second directionwhen the switch detects the firing stroke end.

In various embodiments, a surgical instrument is disclosed. The surgicalinstrument comprises a handle, a shaft comprising a proximal portionextending from the handle and a distal portion, and a firing member. Thesurgical instrument further comprises a motor, wherein the motor isconfigured to be operated in a first direction to advance the firingmember toward the distal end during a firing stroke, wherein the firingstroke comprises a firing stroke end, and wherein the motor isconfigured to be operated in a second direction to retract the firingmember away from the distal end. The surgical instrument furthercomprises means for automatically operating the motor in the seconddirection after the firing member reaches the firing stroke end.

In various embodiments, a surgical instrument system is disclosed. Thesurgical instrument system comprises a handle, an end effectorcomprising a distal end, and a firing member. The surgical instrumentsystem further comprises a motor, wherein the motor is configured to beoperated in a first direction to advance the firing member toward thedistal end during a firing stroke, wherein the firing stroke comprises afiring stroke end, and wherein the motor is configured to be operated ina second direction to retract the firing member away from the distalend, a sensor configured to sense a condition when the firing member isreaching the firing stroke end, and a controller configured toautomatically operate the motor in the second direction when the sensorsenses the condition.

In various embodiments, a surgical instrument system is disclosed. Thesurgical instrument system comprises a handle, an end effectorcomprising a distal end, and a firing member. The surgical instrumentsystem further comprises a motor, wherein the motor is configured to beoperated in a first direction to advance the firing member toward thedistal end during a firing stroke, wherein the firing stroke comprises afiring stroke end, and wherein the motor is configured to be operated ina second direction to retract the firing member away from the distalend, a sensor configured to sense a condition when the firing member hasreached the firing stroke end, and means for applying a first polarityto the motor prior to the sensor detecting the firing stroke end and forapplying a polarity to the motor after sensor detects the firing strokeend.

DRAWINGS

Various embodiments of the present invention are described herein by wayof example in conjunction with the following figures, wherein

FIGS. 1 and 2 are perspective views of a surgical cutting and fasteninginstrument according to various embodiments of the present invention;

FIGS. 3-5 are exploded views of an end effector and shaft of theinstrument according to various embodiments of the present invention;

FIG. 6 is a side view of the end effector according to variousembodiments of the present invention;

FIG. 7 is an exploded view of the handle of the instrument according tovarious embodiments of the present invention;

FIGS. 8 and 9 are partial perspective views of the handle according tovarious embodiments of the present invention;

FIG. 10 is a side view of the handle according to various embodiments ofthe present invention;

FIGS. 10A and 10B illustrate a proportional sensor that may be usedaccording to various embodiments of the present invention;

FIG. 11 is a schematic diagram of a circuit used in the instrumentaccording to various embodiments of the present invention;

FIGS. 12-13 are side views of the handle according to other embodimentsof the present invention;

FIGS. 14-22 illustrate different mechanisms for locking the closuretrigger according to various embodiments of the present invention;

FIGS. 23A-B show a universal joint (“u-joint”) that may be employed atthe articulation point of the instrument according to variousembodiments of the present invention;

FIGS. 24A-B shows a torsion cable that may be employed at thearticulation point of the instrument according to various embodiments ofthe present invention;

FIGS. 25-31 illustrate a surgical cutting and fastening instrument withpower assist according to another embodiment of the present invention;

FIGS. 32-36 illustrate a surgical cutting and fastening instrument withpower assist according to yet another embodiment of the presentinvention;

FIGS. 37-40 illustrate a surgical cutting and fastening instrument withtactile feedback to embodiments of the present invention;

FIG. 41 illustrates an exploded view of an end effector and shaft of theinstrument according to various embodiments of the present invention;

FIG. 42 illustrates a side view of the handle of a mechanicallyinstrument according to various embodiments of the present invention;

FIG. 43 illustrates an exploded view of the handle of the mechanicallyactuated instrument of FIG. 42;

FIG. 44 illustrates a block diagram of a recording system for recordingvarious conditions of the instrument according to various embodiments ofthe present invention;

FIGS. 45-46 illustrate cut away side views of a handle of the instrumentshowing various sensors according to various embodiments of the presentinvention;

FIG. 47 illustrates the end effector of the instrument showing varioussensors according to various embodiments of the present invention;

FIG. 48 illustrates a firing bar of the instrument including a sensoraccording to various embodiments of the present invention;

FIG. 49 illustrates a side view of the handle, end effector, and firingbar of the instrument showing a sensor according to various embodimentsof the present invention;

FIG. 50 illustrates an exploded view of the staple channel and portionsof a staple cartridge of the instrument showing various sensorsaccording to various embodiments of the present invention;

FIG. 51 illustrates a top down view of the staple channel of theinstrument showing various sensors according to various embodiments ofthe present invention;

FIGS. 52A and 52B illustrate a flow chart showing a method for operatingthe instrument according to various embodiments; and

FIG. 53 illustrates a memory chart showing exemplary recorded conditionsof the instrument according to various embodiments of the presentinvention.

DETAILED DESCRIPTION

FIGS. 1 and 2 depict a surgical cutting and fastening instrument 10according to various embodiments of the present invention. Theillustrated embodiment is an endoscopic surgical instrument 10 and ingeneral, the embodiments of the instrument 10 described herein areendoscopic surgical cutting and fastening instruments. It should benoted, however, that according to other embodiments of the presentinvention, the instrument 10 may be a non-endoscopic surgical cuttinginstrument, such as a laproscopic instrument.

The surgical instrument 10 depicted in FIGS. 1 and 2 comprises a handle6, a shaft 8, and an articulating end effector 12 pivotally connected tothe shaft 8 at an articulation pivot 14. An articulation control 16 maybe provided adjacent to the handle 6 to effect rotation of the endeffector 12 about the articulation pivot 14. It will be appreciated thatvarious embodiments may include a non-pivoting end effector, andtherefore may not have an articulation pivot 14 or articulation control16. Also, in the illustrated embodiment, the end effector 12 isconfigured to act as an endocutter for clamping, severing and staplingtissue, although, in other embodiments, different types of end effectorsmay be used, such as end effectors for other types of surgical devices,such as graspers, cutters, staplers, clip appliers, access devices,drug/gene therapy devices, ultrasound, RF or laser devices, etc.

The handle 6 of the instrument 10 may include a closure trigger 18 and afiring trigger 20 for actuating the end effector 12. It will beappreciated that instruments having end effectors directed to differentsurgical tasks may have different numbers or types of triggers or othersuitable controls for operating the end effector 12. The end effector 12is shown separated from the handle 6 by a preferably elongate shaft 8.In one embodiment, a clinician or operator of the instrument 10 mayarticulate the end effector 12 relative to the shaft 8 by utilizing thearticulation control 16, as described in more detail in U.S. patentapplication Ser. No. 11/329,020, filed Jan. 10, 2006, entitled “SurgicalInstrument Having An Articulating End Effector,” by Geoffrey C. Hueil etal., now U.S. Pat. No. 7,670,334, which is incorporated herein byreference.

The end effector 12 includes in this example, among other things, astaple channel 22 and a pivotally translatable clamping member, such asan anvil 24, which are maintained at a spacing that assures effectivestapling and severing of tissue clamped in the end effector 12. Thehandle 6 includes a pistol grip 26 toward which a closure trigger 18 ispivotally drawn by the clinician to cause clamping or closing of theanvil 24 towards the staple channel 22 of the end effector 12 to therebyclamp tissue positioned between the anvil 24 and channel 22. The firingtrigger 20 is farther outboard of the closure trigger 18. Once theclosure trigger 18 is locked in the closure position as furtherdescribed below, the firing trigger 20 may rotate slightly toward thepistol grip 26 so that it can be reached by the operator using one hand.Then the operator may pivotally draw the firing trigger 20 toward thepistol grip 26 to cause the stapling and severing of clamped tissue inthe end effector 12. In other embodiments, different types of clampingmembers besides the anvil 24 could be used, such as, for example, anopposing jaw, etc.

It will be appreciated that the terms “proximal” and “distal” are usedherein with reference to a clinician gripping the handle 6 of aninstrument 10. Thus, the end effector 12 is distal with respect to themore proximal handle 6. It will be further appreciated that, forconvenience and clarity, spatial terms such as “vertical” and“horizontal” are used herein with respect to the drawings. However,surgical instruments are used in many orientations and positions, andthese terms are not intended to be limiting and absolute.

The closure trigger 18 may be actuated first. Once the clinician issatisfied with the positioning of the end effector 12, the clinician maydraw back the closure trigger 18 to its fully closed, locked positionproximate to the pistol grip 26. The firing trigger 20 may then beactuated. The firing trigger 20 returns to the open position (shown inFIGS. 1 and 2) when the clinician removes pressure, as described morefully below. A release button on the handle 6, when depressed mayrelease the locked closure trigger 18. The release button may beimplemented in various forms such as, for example, release button 30shown in FIGS. 42-43, slide release button 160 shown in FIG. 14, and/orbutton 172 shown in FIG. 16.

FIGS. 3-6 show embodiments of a rotary-driven end effector 12 and shaft8 according to various embodiments. FIG. 3 is an exploded view of theend effector 12 according to various embodiments. As shown in theillustrated embodiment, the end effector 12 may include, in addition tothe previously-mentioned channel 22 and anvil 24, a cutting instrument32, a sled 33, a staple cartridge 34 that is removably seated in thechannel 22, and a helical screw shaft 36. The cutting instrument 32 maybe, for example, a knife. The anvil 24 may be pivotably opened andclosed at pivot pins 25 connected to the proximate end of the channel22. The anvil 24 may also include a tab 27 at its proximate end that isinserted into a component of the mechanical closure system (describedfurther below) to open and close the anvil 24. When the closure trigger18 is actuated, that is, drawn in by a user of the instrument 10, theanvil 24 may pivot about the pivot pins 25 into the clamped or closedposition. If clamping of the end effector 12 is satisfactory, theoperator may actuate the firing trigger 20, which, as explained in moredetail below, causes the knife 32 and sled 33 to travel longitudinallyalong the channel 22, thereby cutting tissue clamped within the endeffector 12. The movement of the sled 33 along the channel 22 causes thestaples (not shown) of the staple cartridge 34 to be driven through thesevered tissue and against the closed anvil 24, which turns the staplesto fasten the severed tissue. In various embodiments, the sled 33 may bean integral component of the cartridge 34. U.S. Pat. No. 6,978,921,entitled “SURGICAL STAPLING INSTRUMENT INCORPORATING AN E-BEAM FIRINGMECHANISM” to Shelton, IV et al., which is incorporated herein byreference, provides more details about such two-stroke cutting andfastening instruments. The sled 33 may be part of the cartridge 34, suchthat when the knife 32 retracts following the cutting operation, thesled 33 does not retract.

It should be noted that although the embodiments of the instrument 10described herein employ an end effector 12 that staples the severedtissue, in other embodiments different techniques for fastening orsealing the severed tissue may be used. For example, end effectors thatuse RF energy or adhesives to fasten the severed tissue may also beused. U.S. Pat. No. 5,709,680 entitled “ELECTROSURGICAL HEMOSTATICDEVICE” to Yates et al., and U.S. Pat. No. 5,688,270 entitled“ELECTOSURGICAL HEMOSTATIC DEVICE WITH RECESSED AND/OR OFFSETELECTRODES” to Yates et al. which are incorporated herein by reference,disclose an endoscopic cutting instrument that uses RF energy to sealthe severed tissue. U.S. patent application Ser. No. 11/267,811 toJerome R. Morgan, et. al, now U.S. Pat. No. 7,673,783, and U.S. patentapplication Ser. No. 11/267,383 to Frederick E. Shelton, IV, et. al, nowU.S. Pat. No. 7,607,557, which are also incorporated herein byreference, disclose cutting instruments that uses adhesives to fastenthe severed tissue. Accordingly, although the description herein refersto cutting/stapling operations and the like below, it should berecognized that this is an exemplary embodiment and is not meant to belimiting. Other tissue fastening techniques may also be used.

FIGS. 4 and 5 are exploded views and FIG. 6 is a side view of the endeffector 12 and shaft 8 according to various embodiments. As shown inthe illustrated embodiment, the shaft 8 may include a proximate closuretube 40 and a distal closure tube 42 pivotably linked by a pivot link44. The distal closure tube 42 includes an opening 45 into which the tab27 on the anvil 24 is inserted in order to open and close the anvil 24,as further described below. Disposed inside the closure tubes 40, 42 maybe a proximate spine tube 46. Disposed inside the proximate spine tube46 may be a main rotational (or proximate) drive shaft 48 thatcommunicates with a secondary (or distal) drive shaft 50 via a bevelgear assembly 52. The secondary drive shaft 50 is connected to a drivegear 54 that engages a proximate drive gear 56 of the helical screwshaft 36. The vertical bevel gear 52 b may sit and pivot in an opening57 in the distal end of the proximate spine tube 46. A distal spine tube58 may be used to enclose the secondary drive shaft 50 and the drivegears 54, 56. Collectively, the main drive shaft 48, the secondary driveshaft 50, and the articulation assembly (e.g., the bevel gear assembly52 a-c) are sometimes referred to herein as the “main drive shaftassembly.”

A bearing 38, positioned at a distal end of the staple channel 22,receives the helical drive screw 36, allowing the helical drive screw 36to freely rotate with respect to the channel 22. The helical screw shaft36 may interface a threaded opening (not shown) of the knife 32 suchthat rotation of the shaft 36 causes the knife 32 to translate distallyor proximately (depending on the direction of the rotation) through thestaple channel 22. Accordingly, when the main drive shaft 48 is causedto rotate by actuation of the firing trigger 20 (as explained in moredetail below), the bevel gear assembly 52 a-c causes the secondary driveshaft 50 to rotate, which in turn, because of the engagement of thedrive gears 54, 56, causes the helical screw shaft 36 to rotate, whichcauses the knife driving member 32 to travel longitudinally along thechannel 22 to cut any tissue clamped within the end effector 12. Thesled 33 may be made of, for example, plastic, and may have a slopeddistal surface. As the sled 33 traverses the channel 22, the slopedforward surface may push up or drive the staples in the staple cartridgethrough the clamped tissue and against the anvil 24. The anvil 24 turnsthe staples, thereby stapling the severed tissue. When the knife 32 isretracted, the knife 32 and sled 33 may become disengaged, therebyleaving the sled 33 at the distal end of the channel 22.

As described above, because of the lack of user feedback for thecutting/stapling operation, there is a general lack of acceptance amongphysicians of motor-driven endocutters where the cutting/staplingoperation is actuated by merely pressing a button. In contrast,embodiments of the present invention provide a motor-driven endocutterwith user-feedback of the deployment, force and/or position of thecutting instrument 32 in end effector 12.

FIGS. 7-10 illustrate an exemplary embodiment of a motor-drivenendocutter, and in particular the handle thereof, that providesuser-feedback regarding the deployment and loading force of the cuttinginstrument 32 in the end effector 12. In addition, the embodiment mayuse power provided by the user in retracting the firing trigger 20 topower the device (a so-called “power assist” mode). The embodiment maybe used with the rotary driven end effector 12 and shaft 8 embodimentsdescribed above. As shown in the illustrated embodiment, the handle 6includes exterior lower side pieces 59, 60 and exterior upper sidepieces 61, 62 that fit together to form, in general, the exterior of thehandle 6. A battery 64, such as a Li ion battery, may be provided in thepistol grip portion 26 of the handle 6. The battery 64 powers a motor 65disposed in an upper portion of the pistol grip portion 26 of the handle6. According to various embodiments, the motor 65 may be a DC brusheddriving motor having a maximum rotation of, approximately, 5000 RPM. Themotor 65 may drive a 90° bevel gear assembly 66 comprising a first bevelgear 68 and a second bevel gear 70. The bevel gear assembly 66 may drivea planetary gear assembly 72. The planetary gear assembly 72 may includea pinion gear 74 connected to a drive shaft 76. The pinion gear 74 maydrive a mating ring gear 78 that drives a helical gear drum 80 via adrive shaft 82. A ring 84 may be threaded on the helical gear drum 80.Thus, when the motor 65 rotates, the ring 84 is caused to travel alongthe helical gear drum 80 by means of the interposed bevel gear assembly66, planetary gear assembly 72 and ring gear 78.

The handle 6 may also include a run motor sensor 110 (see FIG. 10) incommunication with the firing trigger 20 to detect when the firingtrigger 20 has been drawn in (or “closed”) toward the pistol gripportion 26 of the handle 6 by the operator to thereby actuate thecutting/stapling operation by the end effector 12. The sensor 110 may bea proportional sensor such as, for example, a rheostat or variableresistor. When the firing trigger 20 is drawn in, the sensor 110 detectsthe movement, and sends an electrical signal indicative of the voltage(or power) to be supplied to the motor 65. When the sensor 110 is avariable resistor or the like, the rotation of the motor 65 may begenerally proportional to the amount of movement of the firing trigger20. That is, if the operator only draws or closes the firing trigger 20in a little bit, the rotation of the motor 65 is relatively low. Whenthe firing trigger 20 is fully drawn in (or in the fully closedposition), the rotation of the motor 65 is at its maximum. In otherwords, the harder the user pulls on the firing trigger 20, the morevoltage is applied to the motor 65, causing greater rates of rotation.

The handle 6 may include a middle handle piece 104 adjacent to the upperportion of the firing trigger 20. The handle 6 also may comprise a biasspring 112 connected between posts on the middle handle piece 104 andthe firing trigger 20. The bias spring 112 may bias the firing trigger20 to its fully open position. In that way, when the operator releasesthe firing trigger 20, the bias spring 112 will pull the firing trigger20 to its open position, thereby removing actuation of the sensor 110,thereby stopping rotation of the motor 65. Moreover, by virtue of thebias spring 112, any time a user closes the firing trigger 20, the userwill experience resistance to the closing operation, thereby providingthe user with feedback as to the amount of rotation exerted by the motor65. Further, the operator could stop retracting the firing trigger 20 tothereby remove force from the sensor 100, to thereby stop the motor 65.As such, the user may stop the deployment of the end effector 12,thereby providing a measure of control of the cutting/fasteningoperation to the operator.

The distal end of the helical gear drum 80 includes a distal drive shaft120 that drives a ring gear 122, which mates with a pinion gear 124. Thepinion gear 124 is connected to the main drive shaft 48 of the maindrive shaft assembly. In that way, rotation of the motor 65 causes themain drive shaft assembly to rotate, which causes actuation of the endeffector 12, as described above.

The ring 84 threaded on the helical gear drum 80 may include a post 86that is disposed within a slot 88 of a slotted arm 90. The slotted arm90 has an opening 92 its opposite end 94 that receives a pivot pin 96that is connected between the handle exterior side pieces 59, 60. Thepivot pin 96 is also disposed through an opening 100 in the firingtrigger 20 and an opening 102 in the middle handle piece 104.

In addition, the handle 6 may include a reverse motor sensor (orend-of-stroke sensor) 130 and a stop motor (or beginning-of-stroke)sensor 142. In various embodiments, the reverse motor sensor 130 may bea limit switch located at the distal end of the helical gear drum 80such that the ring 84 threaded on the helical gear drum 80 contacts andtrips the reverse motor sensor 130 when the ring 84 reaches the distalend of the helical gear drum 80. The reverse motor sensor 130, whenactivated, sends a signal to the motor 65 to reverse its rotationdirection, thereby withdrawing the knife 32 of the end effector 12following the cutting operation.

The stop motor sensor 142 may be, for example, a normally-closed limitswitch. In various embodiments, it may be located at the proximate endof the helical gear drum 80 so that the ring 84 trips the switch 142when the ring 84 reaches the proximate end of the helical gear drum 80.

In operation, when an operator of the instrument 10 pulls back thefiring trigger 20, the sensor 110 detects the deployment of the firingtrigger 20 and sends a signal to the motor 65 to cause forward rotationof the motor 65, for example, at a rate proportional to how hard theoperator pulls back the firing trigger 20. The forward rotation of themotor 65 in turn causes the ring gear 78 at the distal end of theplanetary gear assembly 72 to rotate, thereby causing the helical geardrum 80 to rotate, causing the ring 84 threaded on the helical gear drum80 to travel distally along the helical gear drum 80. The rotation ofthe helical gear drum 80 also drives the main drive shaft assembly asdescribed above, which in turn causes deployment of the knife 32 in theend effector 12. That is, the knife 32 and sled 33 are caused totraverse the channel 22 longitudinally, thereby cutting tissue clampedin the end effector 12. Also, the stapling operation of the end effector12 is caused to happen in embodiments where a stapling-type end effector12 is used.

By the time the cutting/stapling operation of the end effector 12 iscomplete, the ring 84 on the helical gear drum 80 will have reached thedistal end of the helical gear drum 80, thereby causing the reversemotor sensor 130 to be tripped, which sends a signal to the motor 65 tocause the motor 65 to reverse its rotation. This in turn causes theknife 32 to retract, and also causes the ring 84 on the helical geardrum 80 to move back to the proximate end of the helical gear drum 80.

The middle handle piece 104 includes a backside shoulder 106 thatengages the slotted arm 90 as best shown in FIGS. 8 and 9. The middlehandle piece 104 also has a forward motion stop 107 that engages thefiring trigger 20. The movement of the slotted arm 90 is controlled, asexplained above, by rotation of the motor 65. When the slotted arm 90rotates counter clockwise as the ring 84 travels from the proximate endof the helical gear drum 80 to the distal end, the middle handle piece104 will be free to rotate counter clockwise. Thus, as the user draws inthe firing trigger 20, the firing trigger 20 will engage the forwardmotion stop 107 of the middle handle piece 104, causing the middlehandle piece 104 to rotate counter clockwise. Due to the backsideshoulder 106 engaging the slotted arm 90, however, the middle handlepiece 104 will only be able to rotate counter clockwise as far as theslotted arm 90 permits. In that way, if the motor 65 should stoprotating for some reason, the slotted arm 90 will stop rotating, and theuser will not be able to further draw in the firing trigger 20 becausethe middle handle piece 104 will not be free to rotate counter clockwisedue to the slotted arm 90.

FIGS. 10A and 10B illustrate two states of a variable sensor that may beused as the run motor sensor 110 according to various embodiments of thepresent invention. The sensor 110 may include a face portion 280, afirst electrode (A) 282, a second electrode (B) 284, and a compressibledielectric material 286 between the electrodes 282, 284, such as, forexample, an electroactive polymer (EAP). The sensor 110 may bepositioned such that the face portion 280 contacts the firing trigger 20when retracted. Accordingly, when the firing trigger 20 is retracted,the dielectric material 286 is compressed, as shown in FIG. 10B, suchthat the electrodes 282, 284 are closer together. Since the distance “b”between the electrodes 282, 284 is directly related to the impedancebetween the electrodes 282, 284, the greater the distance the moreimpedance, and the closer the distance the less impedance. In that way,the amount that the dielectric 286 is compressed due to retraction ofthe firing trigger 20 (denoted as force “F” in FIG. 42) is proportionalto the impedance between the electrodes 282, 284, which can be used toproportionally control the motor 65.

Components of an exemplary closure system for closing (or clamping) theanvil 24 of the end effector 12 by retracting the closure trigger 18 arealso shown in FIGS. 7-10. In the illustrated embodiment, the closuresystem includes a yoke 250 connected to the closure trigger 18 by apivot pin 251 inserted through aligned openings in both the closuretrigger 18 and the yoke 250. A pivot pin 252, about which the closuretrigger 18 pivots, is inserted through another opening in the closuretrigger 18 which is offset from where the pin 251 is inserted throughthe closure trigger 18. Thus, retraction of the closure trigger 18causes the upper part of the closure trigger 18, to which the yoke 250is attached via the pin 251, to rotate counterclockwise. The distal endof the yoke 250 is connected, via a pin 254, to a first closure bracket256. The first closure bracket 256 connects to a second closure bracket258. Collectively, the closure brackets 256, 258 define an opening inwhich the proximate end of the proximate closure tube 40 (see FIG. 4) isseated and held such that longitudinal movement of the closure brackets256, 258 causes longitudinal motion by the proximate closure tube 40.The instrument 10 also includes a closure rod 260 disposed inside theproximate closure tube 40. The closure rod 260 may include a window 261into which a post 263 on one of the handle exterior pieces, such asexterior lower side piece 59 in the illustrated embodiment, is disposedto fixedly connect the closure rod 260 to the handle 6. In that way, theproximate closure tube 40 is capable of moving longitudinally relativeto the closure rod 260. The closure rod 260 may also include a distalcollar 267 that fits into a cavity 269 in proximate spine tube 46 and isretained therein by a cap 271 (see FIG. 4).

In operation, when the yoke 250 rotates due to retraction of the closuretrigger 18, the closure brackets 256, 258 cause the proximate closuretube 40 to move distally (i.e., away from the handle end of theinstrument 10), which causes the distal closure tube 42 to movedistally, which causes the anvil 24 to rotate about the pivot pins 25into the clamped or closed position. When the closure trigger 18 isunlocked from the locked position, the proximate closure tube 40 iscaused to slide proximately, which causes the distal closure tube 42 toslide proximately, which, by virtue of the tab 27 being inserted in thewindow 45 of the distal closure tube 42, causes the anvil 24 to pivotabout the pivot pins 25 into the open or unclamped position. In thatway, by retracting and locking the closure trigger 18, an operator mayclamp tissue between the anvil 24 and channel 22, and may unclamp thetissue following the cutting/stapling operation by unlocking the closuretrigger 20 from the locked position.

FIG. 11 is a schematic diagram of an electrical circuit of theinstrument 10 according to various embodiments of the present invention.When an operator initially pulls in the firing trigger 20 after lockingthe closure trigger 18, the sensor 110 is activated, allowing current toflow there through. If the normally-open reverse motor sensor switch 130is open (meaning the end of the end effector stroke has not beenreached), current will flow to a single pole, double throw relay 132.Since the reverse motor sensor switch 130 is not closed, the inductor134 of the relay 132 will not be energized, so the relay 132 will be inits non-energized state. The circuit also includes a cartridge lockoutsensor 136. If the end effector 12 includes a staple cartridge 34, thesensor 136 will be in the closed state, allowing current to flow.Otherwise, if the end effector 12 does not include a staple cartridge34, the sensor 136 will be open, thereby preventing the battery 64 frompowering the motor 65.

When the staple cartridge 34 is present, the sensor 136 is closed, whichenergizes a single pole, single throw relay 138. When the relay 138 isenergized, current flows through the relay 136, through the variableresistor sensor 110, and to the motor 65 via a double pole, double throwrelay 140, thereby powering the motor 65 and allowing it to rotate inthe forward direction.

When the end effector 12 reaches the end of its stroke, the reversemotor sensor 130 will be activated, thereby closing the switch 130 andenergizing the relay 134. This causes the relay 134 to assume itsenergized state (not shown in FIG. 13), which causes current to bypassthe cartridge lockout sensor 136 and variable resistor 110, and insteadcauses current to flow to both the normally-closed double pole, doublethrow relay 142 and back to the motor 65, but in a manner, via the relay140, that causes the motor 65 to reverse its rotational direction.

Because the stop motor sensor switch 142 is normally-closed, currentwill flow back to the relay 134 to keep it closed until the switch 142opens. When the knife 32 is fully retracted, the stop motor sensorswitch 142 is activated, causing the switch 142 to open, therebyremoving power from the motor 65.

In other embodiments, rather than a proportional-type sensor 110, anon-off type sensor could be used. In such embodiments, the rate ofrotation of the motor 65 would not be proportional to the force appliedby the operator. Rather, the motor 65 would generally rotate at aconstant rate. But the operator would still experience force feedbackbecause the firing trigger 20 is geared into the gear drive train.

FIG. 12 is a side-view of the handle 6 of a power-assist motorizedendocutter according to another embodiment. The embodiment of FIG. 12 issimilar to that of FIGS. 7-10 except that in the embodiment of FIG. 12,there is no slotted arm connected to the ring 84 threaded on the helicalgear drum 80. Instead, in the embodiment of FIG. 12, the ring 84includes a sensor portion 114 that moves with the ring 84 as the ring 84advances down (and back) on the helical gear drum 80. The sensor portion114 includes a notch 116. The reverse motor sensor 130 may be located atthe distal end of the notch 116 and the stop motor sensor 142 may belocated at the proximate end of the notch 116. As the ring 84 moves downthe helical gear drum 80 (and back), the sensor portion 114 moves withit. Further, as shown in FIG. 12, the middle piece 104 may have an arm118 that extends into the notch 12.

In operation, as an operator of the instrument 10 retracts in the firingtrigger 20 toward the pistol grip 26, the run motor sensor 110 detectsthe motion and sends a signal to power the motor 65, which causes, amongother things, the helical gear drum 80 to rotate. As the helical geardrum 80 rotates, the ring 84 threaded on the helical gear drum 80advances (or retracts, depending on the rotation). Also, due to thepulling in of the firing trigger 20, the middle piece 104 is caused torotate counter clockwise with the firing trigger 20 due to the forwardmotion stop 107 that engages the firing trigger 20. The counterclockwise rotation of the middle piece 104 cause the arm 118 to rotatecounter clockwise with the sensor portion 114 of the ring 84 such thatthe arm 118 stays disposed in the notch 116. When the ring 84 reachesthe distal end of the helical gear drum 80, the arm 118 will contact andthereby trip the reverse motor sensor 130. Similarly, when the ring 84reaches the proximate end of the helical gear drum 80, the arm willcontact and thereby trip the stop motor sensor 142. Such actions mayreverse and stop the motor 65, respectively as described above.

FIG. 13 is a side-view of the handle 6 of a power-assist motorizedendocutter according to another embodiment. The embodiment of FIG. 13 issimilar to that of FIGS. 7-10 except that in the embodiment of FIG. 13,there is no slot in the arm 90. Instead, the ring 84 threaded on thehelical gear drum 80 includes a vertical channel 126. Instead of a slot,the arm 90 includes a post 128 that is disposed in the channel 126. Asthe helical gear drum 80 rotates, the ring 84 threaded on the helicalgear drum 80 advances (or retracts, depending on the rotation). The arm90 rotates counter clockwise as the ring 84 advances due to the post 128being disposed in the channel 126, as shown in FIG. 13.

As mentioned above, in using a two-stroke motorized instrument, theoperator first pulls back and locks the closure trigger 18. FIGS. 14 and15 show one embodiment of a way to lock the closure trigger 18 to thepistol grip portion 26 of the handle 6. In the illustrated embodiment,the pistol grip portion 26 includes a hook 150 that is biased to rotatecounter clockwise about a pivot point 151 by a torsion spring 152. Also,the closure trigger 18 includes a closure bar 154. As the operator drawsin the closure trigger 18, the closure bar 154 engages a sloped portion156 of the hook 150, thereby rotating the hook 150 upward (or clockwisein FIGS. 14-15) until the closure bar 154 completely passes the slopedportion 156 passes into a recessed notch 158 of the hook 150, whichlocks the closure trigger 18 in place. The operator may release theclosure trigger 18 by pushing down on a slide button release 160 on theback or opposite side of the pistol grip portion 26. Pushing down theslide button release 160 rotates the hook 150 clockwise such that theclosure bar 154 is released from the recessed notch 158.

FIG. 16 shows another closure trigger locking mechanism according tovarious embodiments. In the embodiment of FIG. 16, the closure trigger18 includes a wedge 160 having an arrow-head portion 161. The arrow-headportion 161 is biased downward (or clockwise) by a leaf spring 162. Thewedge 160 and leaf spring 162 may be made from, for example, moldedplastic. When the closure trigger 18 is retracted, the arrow-headportion 161 is inserted through an opening 164 in the pistol gripportion 26 of the handle 6. A lower chamfered surface 166 of thearrow-head portion 161 engages a lower sidewall 168 of the opening 164,forcing the arrow-head portion 161 to rotate counter clockwise.Eventually the lower chamfered surface 166 fully passes the lowersidewall 168, removing the counter clockwise force on the arrow-headportion 161, causing the lower sidewall 168 to slip into a lockedposition in a notch 170 behind the arrow-head portion 161.

To unlock the closure trigger 18, a user presses down on a button 172 onthe opposite side of the closure trigger 18, causing the arrow-headportion 161 to rotate counter clockwise and allowing the arrow-headportion 161 to slide out of the opening 164.

FIGS. 17-22 show a closure trigger locking mechanism according toanother embodiment. As shown in this embodiment, the closure trigger 18includes a flexible longitudinal arm 176 that includes a lateral pin 178extending therefrom. The arm 176 and pin 178 may be made from moldedplastic, for example. The pistol grip portion 26 of the handle 6includes an opening 180 with a laterally extending wedge 182 disposedtherein. When the closure trigger 18 is retracted, the pin 178 engagesthe wedge 182, and the pin 178 is forced downward (i.e., the arm 176 isrotated clockwise) by the lower surface 184 of the wedge 182, as shownin FIGS. 17 and 18. When the pin 178 fully passes the lower surface 184,the clockwise force on the arm 176 is removed, and the pin 178 isrotated counter clockwise such that the pin 178 comes to rest in a notch186 behind the wedge 182, as shown in FIG. 19, thereby locking theclosure trigger 18. The pin 178 is further held in place in the lockedposition by a flexible stop 188 extending from the wedge 184.

To unlock the closure trigger 18, the operator may further squeeze theclosure trigger 18, causing the pin 178 to engage a sloped backwall 190of the opening 180, forcing the pin 178 upward past the flexible stop188, as shown in FIGS. 20 and 21. The pin 178 is then free to travel outan upper channel 192 in the opening 180 such that the closure trigger 18is no longer locked to the pistol grip portion 26, as shown in FIG. 22.

FIGS. 23A-B show a universal joint (“u-joint”) 195. The second piece195-2 of the u-joint 195 rotates in a horizontal plane in which thefirst piece 195-1 lies. FIG. 23A shows the u-joint 195 in a linear(180°) orientation and FIG. 23B shows the u-joint 195 at approximately a150° orientation. The u-joint 195 may be used instead of the bevel gears52 a-c (see FIG. 4, for example) at the articulation point 14 of themain drive shaft assembly to articulate the end effector 12. FIGS. 24A-Bshow a torsion cable 197 that may be used in lieu of both the bevelgears 52 a-c and the u-joint 195 to realize articulation of the endeffector 12.

FIGS. 25-31 illustrate another embodiment of a motorized, two-strokesurgical cutting and fastening instrument 10 with power assist accordingto another embodiment of the present invention. The embodiment of FIGS.25-31 is similar to that of FIGS. 6-10 except that instead of thehelical gear drum 80, the embodiment of FIGS. 23-28 includes analternative gear drive assembly. The embodiment of FIGS. 25-31 includesa gear box assembly 200 including a number of gears disposed in a frame201, wherein the gears are connected between the planetary gear 72 andthe pinion gear 124 at the proximate end of the drive shaft 48. Asexplained further below, the gear box assembly 200 provides feedback tothe user via the firing trigger 20 regarding the deployment and loadingforce of the end effector 12. Also, the user may provide power to thesystem via the gear box assembly 200 to assist the deployment of the endeffector 12. In that sense, like the embodiments described above, theembodiment of FIGS. 23-32 is another power assist motorized instrument10 that provides feedback to the user regarding the loading forceexperienced by the instrument.

In the illustrated embodiment, the firing trigger 20 includes twopieces: a main body portion 202 and a stiffening portion 204. The mainbody portion 202 may be made of plastic, for example, and the stiffeningportion 204 may be made out of a more rigid material, such as metal. Inthe illustrated embodiment, the stiffening portion 204 is adjacent tothe main body portion 202, but according to other embodiments, thestiffening portion 204 could be disposed inside the main body portion202. A pivot pin 207 may be inserted through openings in the firingtrigger pieces 202, 204 and may be the point about which the firingtrigger 20 rotates. In addition, a spring 222 may bias the firingtrigger 20 to rotate in a counter clockwise direction. The spring 222may have a distal end connected to a pin 224 that is connected to thepieces 202, 204 of the firing trigger 20. The proximate end of thespring 222 may be connected to one of the handle exterior lower sidepieces 59, 60.

In the illustrated embodiment, both the main body portion 202 and thestiffening portion 204 includes gear portions 206, 208 (respectively) attheir upper end portions. The gear portions 206, 208 engage a gear inthe gear box assembly 200, as explained below, to drive the main driveshaft assembly and to provide feedback to the user regarding thedeployment of the end effector 12.

The gear box assembly 200 may include as shown, in the illustratedembodiment, six (6) gears. A first gear 210 of the gear box assembly 200engages the gear portions 206, 208 of the firing trigger 20. Inaddition, the first gear 210 engages a smaller second gear 212, thesmaller second gear 212 being coaxial with a large third gear 214. Thethird gear 214 engages a smaller fourth gear 216, the smaller fourthgear being coaxial with a fifth gear 218. The fifth gear 218 is a 90°bevel gear that engages a mating 90° bevel gear 220 (best shown in FIG.31) that is connected to the pinion gear 124 that drives the main driveshaft 48.

In operation, when the user retracts the firing trigger 20, a run motorsensor (not shown) is activated, which may provide a signal to the motor65 to rotate at a rate proportional to the extent or force with whichthe operator is retracting the firing trigger 20. This causes the motor65 to rotate at a speed proportional to the signal from the sensor. Thesensor is not shown for this embodiment, but it could be similar to therun motor sensor 110 described above. The sensor could be located in thehandle 6 such that it is depressed when the firing trigger 20 isretracted. Also, instead of a proportional-type sensor, an on/off typesensor may be used.

Rotation of the motor 65 causes the bevel gears 68, 70 to rotate, whichcauses the planetary gear 72 to rotate, which causes, via the driveshaft 76, the ring gear 122 to rotate. The ring gear 122 meshes with thepinion gear 124, which is connected to the main drive shaft 48. Thus,rotation of the pinion gear 124 drives the main drive shaft 48, whichcauses actuation of the cutting/stapling operation of the end effector12.

Forward rotation of the pinion gear 124 in turn causes the bevel gear220 to rotate, which causes, by way of the rest of the gears of the gearbox assembly 200, the first gear 210 to rotate. The first gear 210engages the gear portions 206, 208 of the firing trigger 20, therebycausing the firing trigger 20 to rotate counter clockwise when the motor65 provides forward drive for the end effector 12 (and to rotate counterclockwise when the motor 65 rotates in reverse to retract the endeffector 12). In that way, the user experiences feedback regardingloading force and deployment of the end effector 12 by way of the user'sgrip on the firing trigger 20. Thus, when the user retracts the firingtrigger 20, the operator will experience a resistance related to theload force experienced by the end effector 12. Similarly, when theoperator releases the firing trigger 20 after the cutting/staplingoperation so that it can return to its original position, the user willexperience a clockwise rotation force from the firing trigger 20 that isgenerally proportional to the reverse speed of the motor 65.

It should also be noted that in this embodiment the user can apply force(either in lieu of or in addition to the force from the motor 65) toactuate the main drive shaft assembly (and hence the cutting/staplingoperation of the end effector 12) through retracting the firing trigger20. That is, retracting the firing trigger 20 causes the gear portions206, 208 to rotate counter clockwise, which causes the gears of the gearbox assembly 200 to rotate, thereby causing the pinion gear 124 torotate, which causes the main drive shaft 48 to rotate.

Although not shown in FIGS. 25-31, the instrument 10 may further includereverse motor and stop motor sensors. As described above, the reversemotor and stop motor sensors may detect, respectively, the end of thecutting stroke (full deployment of the knife 32) and the end ofretraction operation (full retraction of the knife 32). A similarcircuit to that described above in connection with FIG. 11 may be usedto appropriately power the motor 65.

FIGS. 32-36 illustrate a two-stroke, motorized surgical cutting andfastening instrument 10 with power assist according to anotherembodiment. The embodiment of FIGS. 32-36 is similar to that of FIGS.25-31 except that in the embodiment of FIGS. 32-36, the firing trigger20 includes a lower portion 228 and an upper portion 230. Both portions228, 230 are connected to and pivot about a pivot pin 207 that isdisposed through each portion 228, 230. The upper portion 230 includes agear portion 232 that engages the first gear 210 of the gear boxassembly 200. The spring 222 is connected to the upper portion 230 suchthat the upper portion is biased to rotate in the clockwise direction.The upper portion 230 may also include a lower arm 234 that contacts anupper surface of the lower portion 228 of the firing trigger 20 suchthat when the upper portion 230 is caused to rotate clockwise the lowerportion 228 also rotates clockwise, and when the lower portion 228rotates counter clockwise the upper portion 230 also rotates counterclockwise. Similarly, the lower portion 228 includes a rotational stop238 that engages a shoulder of the upper portion 230. In that way, whenthe upper portion 230 is caused to rotate counter clockwise the lowerportion 228 also rotates counter clockwise, and when the lower portion228 rotates clockwise the upper portion 230 also rotates clockwise.

The illustrated embodiment also includes the run motor sensor 110 thatcommunicates a signal to the motor 65 that, in various embodiments, maycause the motor 65 to rotate at a speed proportional to the forceapplied by the operator when retracting the firing trigger 20. Thesensor 110 may be, for example, a rheostat or some other variableresistance sensor, as explained herein. In addition, the instrument 10may include reverse motor sensor 130 that is tripped or switched whencontacted by a front face 242 of the upper portion 230 of the firingtrigger 20. When activated, the reverse motor sensor 130 sends a signalto the motor 65 to reverse direction. Also, the instrument 10 mayinclude a stop motor sensor 142 that is tripped or actuated whencontacted by the lower portion 228 of the firing trigger 20. Whenactivated, the stop motor sensor 142 sends a signal to stop the reverserotation of the motor 65.

In operation, when an operator retracts the closure trigger 18 into thelocked position, the firing trigger 20 is retracted slightly (throughmechanisms known in the art, including U.S. Pat. No. 6,978,921 toFrederick Shelton, IV et. al and U.S. Pat. No. 6,905,057 to Jeffery S.Swayze et. al, which are incorporated herein by reference) so that theuser can grasp the firing trigger 20 to initiate the cutting/staplingoperation, as shown in FIGS. 32 and 33. At that point, as shown in FIG.33, the gear portion 232 of the upper portion 230 of the firing trigger20 moves into engagement with the first gear 210 of the gear boxassembly 200. When the operator retracts the firing trigger 20,according to various embodiments, the firing trigger 20 may rotate asmall amount, such as five degrees, before tripping the run motor sensor110, as shown in FIG. 34. Activation of the sensor 110 causes the motor65 to forward rotate at a rate proportional to the retraction forceapplied by the operator. The forward rotation of the motor 65 causes, asdescribed above, the main drive shaft 48 to rotate, which causes theknife 32 in the end effector 12 to be deployed (i.e., begin traversingthe channel 22). Rotation of the pinion gear 124, which is connected tothe main drive shaft 48, causes the gears 210-220 in the gear boxassembly 200 to rotate. Since the first gear 210 is in engagement withthe gear portion 232 of the upper portion 230 of the firing trigger 20,the upper portion 232 is caused to rotate counter clockwise, whichcauses the lower portion 228 to also rotate counter clockwise.

When the knife 32 is fully deployed (i.e., at the end of the cuttingstroke), the front face 242 of the upper portion 230 trips the reversemotor sensor 130, which sends a signal to the motor 65 to reverserotational directional. This causes the main drive shaft assembly toreverse rotational direction to retract the knife 32. Reverse rotationof the main drive shaft assembly also causes the gears 210-220 in thegear box assembly to reverse direction, which causes the upper portion230 of the firing trigger 20 to rotate clockwise, which causes the lowerportion 228 of the firing trigger 20 to rotate clockwise until the lowerportion 228 trips or actuates the stop motor sensor 142 when the knife32 is fully retracted, which causes the motor 65 to stop. In that way,the user experiences feedback regarding deployment of the end effector12 by way of the user's grip on the firing trigger 20. Thus, when theuser retracts the firing trigger 20, the operator will experience aresistance related to the deployment of the end effector 12 and, inparticular, to the loading force experienced by the knife 32. Similarly,when the operator releases the firing trigger 20 after thecutting/stapling operation so that it can return to its originalposition, the user will experience a clockwise rotation force from thefiring trigger 20 that is generally proportional to the reverse speed ofthe motor 65.

It should also be noted that in this embodiment the user can apply force(either in lieu of or in addition to the force from the motor 65) toactuate the main drive shaft assembly (and hence the cutting/staplingoperation of the end effector 12) through retracting the firing trigger20. That is, retracting the firing trigger 20 causes the gear portion232 of the upper portion 230 to rotate counter clockwise, which causesthe gears of the gear box assembly 200 to rotate, thereby causing thepinion gear 124 to rotate, which causes the main drive shaft assembly torotate.

The above-described embodiments employed power-assist user feedbacksystems, with or without adaptive control (e.g., using a sensor 110,130, and 142 outside of the closed loop system of the motor 65, geardrive train, and end effector 12) for a two-stroke, motorized surgicalcutting and fastening instrument. That is, force applied by the user inretracting the firing trigger 20 may be added to the force applied bythe motor 65 by virtue of the firing trigger 20 being geared into(either directly or indirectly) the gear drive train between the motor65 and the main drive shaft 48. In other embodiments of the presentinvention, the user may be provided with tactile feedback regarding theposition of the knife 32 in the end effector, but without having thefiring trigger 20 geared into the gear drive train. FIGS. 37-40illustrate a motorized surgical cutting and fastening instrument withsuch a tactile position feedback system.

In the illustrated embodiment of FIGS. 37-40, the firing trigger 20 mayhave a lower portion 228 and an upper portion 230, similar to theinstrument 10 shown in FIGS. 32-36. Unlike the embodiment of FIG. 32-36,however, the upper portion 230 does not have a gear portion that mateswith part of the gear drive train. Instead, the instrument includes asecond motor 265 with a threaded rod 266 threaded therein. The threadedrod 266 reciprocates longitudinally in and out of the motor 265 as themotor 265 rotates, depending on the direction of rotation. Theinstrument 10 also includes an encoder 268 that is responsive to therotations of the main drive shaft 48 for translating the incrementalangular motion of the main drive shaft 48 (or other component of themain drive assembly) into a corresponding series of digital signals, forexample. In the illustrated embodiment, the pinion gear 124 includes aproximate drive shaft 270 that connects to the encoder 268.

The instrument 10 also includes a control circuit (not shown), which maybe implemented using a microcontroller or some other type of integratedcircuit, that receives the digital signals from the encoder 268. Basedon the signals from the encoder 268, the control circuit may calculatethe stage of deployment of the knife 32 in the end effector 12. That is,the control circuit can calculate if the knife 32 is fully deployed,fully retracted, or at an intermittent stage. Based on the calculationof the stage of deployment of the end effector 12, the control circuitmay send a signal to the second motor 265 to control its rotation tothereby control the reciprocating movement of the threaded rod 266.

In operation, as shown in FIG. 37, when the closure trigger 18 is notlocked into the clamped position, the firing trigger 20 rotated awayfrom the pistol grip portion 26 of the handle 6 such that the front face242 of the upper portion 230 of the firing trigger 20 is not in contactwith the proximate end of the threaded rod 266. When the operatorretracts the closure trigger 18 and locks it in the clamped position,the firing trigger 20 rotates slightly towards the closure trigger 20 sothat the operator can grasp the firing trigger 20, as shown in FIG. 38.In this position, the front face 242 of the upper portion 230 contactsthe proximate end of the threaded rod 266.

As the user then retracts the firing trigger 20, after an initialrotational amount (e.g. 5 degrees of rotation) the run motor sensor 110may be activated such that, as explained above, the sensor 110 sends asignal to the motor 65 to cause it to rotate at a forward speedproportional to the amount of retraction force applied by the operatorto the firing trigger 20. Forward rotation of the motor 65 causes themain drive shaft 48 to rotate via the gear drive train, which causes theknife 32 and sled 33 to travel down the channel 22 and sever tissueclamped in the end effector 12. The control circuit receives the outputsignals from the encoder 268 regarding the incremental rotations of themain drive shaft assembly and sends a signal to the second motor 265 tocause the second motor 265 to rotate, which causes the threaded rod 266to retract into the motor 265. This allows the upper portion 230 of thefiring trigger 20 to rotate counter clockwise, which allows the lowerportion 228 of the firing trigger to also rotate counter clockwise. Inthat way, because the reciprocating movement of the threaded rod 266 isrelated to the rotations of the main drive shaft assembly, the operatorof the instrument 10, by way of his/her grip on the firing trigger 20,experiences tactile feedback as to the position of the end effector 12.The retraction force applied by the operator, however, does not directlyaffect the drive of the main drive shaft assembly because the firingtrigger 20 is not geared into the gear drive train in this embodiment.

By virtue of tracking the incremental rotations of the main drive shaftassembly via the output signals from the encoder 268, the controlcircuit can calculate when the knife 32 is fully deployed (i.e., fullyextended). At this point, the control circuit may send a signal to themotor 65 to reverse direction to cause retraction of the knife 32. Thereverse direction of the motor 65 causes the rotation of the main driveshaft assembly to reverse direction, which is also detected by theencoder 268. Based on the reverse rotation detected by the encoder 268,the control circuit sends a signal to the second motor 265 to cause itto reverse rotational direction such that the threaded rod 266 starts toextend longitudinally from the motor 265. This motion forces the upperportion 230 of the firing trigger 20 to rotate clockwise, which causesthe lower portion 228 to rotate clockwise. In that way, the operator mayexperience a clockwise force from the firing trigger 20, which providesfeedback to the operator as to the retraction position of the knife 32in the end effector 12. The control circuit can determine when the knife32 is fully retracted. At this point, the control circuit may send asignal to the motor 65 to stop rotation.

According to other embodiments, rather than having the control circuitdetermine the position of the knife 32, reverse motor and stop motorsensors may be used, as described above. In addition, rather than usinga proportional sensor 110 to control the rotation of the motor 65, anon/off switch or sensor can be used. In such an embodiment, the operatorwould not be able to control the rate of rotation of the motor 65.Rather, it would rotate at a preprogrammed rate.

FIGS. 41-43 illustrate an exemplary embodiment of a mechanicallyactuated endocutter, and in particular the handle 6, shaft 8 and endeffector 12 thereof. Further details of a mechanically actuatedendocutter may be found in U.S. patent application Ser. No. 11/052,632entitled, “Surgical Stapling Instrument Incorporating A Multi-StrokeFiring Mechanism With Automatic End Of Firing Travel Retraction,” nowU.S. Pat. No. 7,083,075, which is incorporated herein by reference. Withreference to FIG. 41, the end effector 12 responds to the closure motionfrom the handle 6 (not depicted in FIG. 41) first by including an anvilface 1002 connecting to an anvil proximal end 1004 that includeslaterally projecting anvil pivot pins 25 that are proximal to avertically projecting anvil tab 27. The anvil pivot pins 25 translatewithin kidney shaped openings 1006 in the staple channel 22 to open andclose anvil 24 relative to channel 22. The tab 27 engages a bent tab1007 extending inwardly in tab opening 45 on a distal end 1008 of theclosure tube 1005, the latter distally terminating in a distal edge 1008that pushes against the anvil face 1002. Thus, when the closure tube1005 moves proximally from its open position, the bent tab 1007 of theclosure tube 1005 draws the anvil tab 27 proximally, and the anvil pivotpins 25 follow the kidney shaped openings 1006 of the staple channel 22causing the anvil 24 to simultaneously translate proximally and rotateupward to the open position. When the closure tube 1005 moves distally,the bent tab 1007 in the tab opening 45 releases from the anvil tab 27and the distal edge 1008 pushes on the anvil face 1002, closing theanvil 24.

With continued reference to FIG. 41, the shaft 8 and end effector 12also include components that respond to a firing motion of a firing rod1010. In particular, the firing rod 1010 rotatably engages a firingtrough member 1012 having a longitudinal recess 1014. Firing troughmember 1012 moves longitudinally within frame 1016 in direct response tolongitudinal motion of firing rod 1010. A longitudinal slot 1018 in theclosure tube 1005 operably couples with the right and left exterior sidehandle pieces 61, 62 of the handle 6 (not shown in FIG. 41). The lengthof the longitudinal slot 1018 in the closure tube 1005 is sufficientlylong to allow relative longitudinal motion with the handle pieces 61, 62to accomplish firing and closure motions respectively with the couplingof the handle pieces 61, 62 passing on through a longitudinal slot 1020in the frame 1016 to slidingly engage the longitudinal recess 1014 inthe frame trough member 1012.

The distal end of the frame trough member 1012 is attached to a proximalend of a firing bar 1022 that moves within the frame 1016, specificallywithin a guide 1024 therein, to distally project the knife 32 into theend effector 12. The end effector 12 includes a staple cartridge 34 thatis actuated by the knife 32. The staple cartridge 34 has a tray 1028that holds a staple cartridge body 1030, a wedge sled driver 33, stapledrivers 1034 and staples 1036. It will be appreciated that the wedgesled driver 33 longitudinally moves within a firing recess (not shown)located between the cartridge tray 1028 and the cartridge body 1030. Thewedge sled driver 33 presents camming surfaces that contact and lift thestaple drivers 1034 upward, driving the staples 1036. The staplecartridge body 1030 further includes a proximally open, vertical slot1031 for passage of the knife 32. Specifically, a cutting surface 1027is provided along a distal end of knife 32 to cut tissue after it isstapled.

It should be appreciated that the shaft 8 is shown in FIG. 4 as anon-articulating shaft. Nonetheless, applications of the presentinvention may include instruments capable of articulation, for example,as such shown above with reference to FIGS. 1-4 and described in thefollowing U.S. patents and patent applications, the disclosure of eachbeing hereby incorporated by reference in their entirety: (1) “SURGICALINSTRUMENT INCORPORATING AN ARTICULATION MECHANISM HAVING ROTATION ABOUTTHE LONGITUDINAL AXIS”, U.S. Publication No. 2005/0006434, by FrederickE. Shelton IV, Brian J. Hemmelgarn, Jeffrey S. Swayze, Kenneth S. Wales,filed 9 Jul. 2003, now U.S. Pat. No. 7,111,769; (2) “SURGICAL STAPLINGINSTRUMENT INCORPORATING AN ARTICULATION JOINT FOR A FIRING BAR TRACK”,U.S. Pat. No. 6,786,382, to Brian J. Hemmelgarn; (3) “A SURGICALINSTRUMENT WITH A LATERAL-MOVING ARTICULATION CONTROL”, U.S. Pat. No.6,981,628, to Jeffrey S. Swayze; (4) “SURGICAL STAPLING INSTRUMENTINCORPORATING A TAPERED FIRING BAR FOR INCREASED FLEXIBILITY AROUND THEARTICULATION JOINT”, U.S. Pat. No. 6,964,363, to Frederick E. SheltonIV, Michael Setser, Bruce Weisenburgh II; and (5) “SURGICAL STAPLINGINSTRUMENT HAVING ARTICULATION JOINT SUPPORT PLATES FOR SUPPORTING AFIRING BAR”, U.S. Publication No. 2005/0006431, by Jeffrey S. Swayze,Joseph Charles Hueil, filed 9 Jul. 2003, now U.S. Pat. No. 7,055,731.

FIGS. 42-43 show an embodiment of the handle 6 that is configured foruse in a mechanically actuated endocutter along with the embodiment ofthe shaft 8 and end effector 12 as shown above in FIG. 41. It will beappreciated that any suitable handle design may be used to mechanicallyclose and fire the end effector 12. In FIGS. 42-43, the handle 6 of thesurgical stapling and severing instrument 10 includes a linkedtransmission firing mechanism 1060 that provides features such asincreased strength, reduced handle size, minimized binding, etc.

Closure of the end effector 12 (not shown in FIGS. 42-43) is caused bydepressing the closure trigger 18 toward the pistol grip 26 of handle 6.The closure trigger 18 pivots about a closure pivot pin 252 that iscoupled to right and left exterior lower side pieces 59, 60 the handle6, causing an upper portion 1094 of the closure trigger 18 to moveforward. The closure tube 1005 receives this closure movement via theclosure yoke 250 that is pinned to a closure link 1042 and to the upperportion 1094 of the closure trigger 18 respectively by a closure yokepin 1044 and a closure link pin 1046.

In the fully open position of FIG. 42, the upper portion 1094 of theclosure trigger 18 contacts and holds a locking arm 1048 of the pivotingclosure release button 30 in the position shown. When the closuretrigger 18 reaches its fully depressed position, the closure trigger 18releases the locking arm 1048 and an abutting surface 1050 rotates intoengagement with a distal rightward notch 1052 of the pivoting lockingarm 1048, holding the closure trigger 18 in this clamped or closedposition. A proximal end of the locking arm 1048 pivots about a lateralpivotal connection 1054 with the pieces 59, 60 to expose the closurerelease button 30. An intermediate, distal side 1056 of the closurerelease button 30 is urged proximally by a compression spring 1058,which is compressed between a housing structure 1040 and closure releasebutton 30. The result is that the closure release button 30 urges thelocking arm 1048 counterclockwise (when viewed from the left) intolocking contact with the abutting surface 1050 of closure trigger 18,which prevents unclamping of closure trigger 18 when the linkedtransmission firing system 1040 is in an un-retracted condition.

With the closure trigger 18 retracted and fully depressed, the firingtrigger 20 is unlocked and may be depressed toward the pistol grip 26,multiple times in this embodiment, to effect firing of the end effector12. As depicted, the linked transmission firing mechanism 1060 isinitially retracted, urged to remain in this position by a combinationtension/compression spring 1062 that is constrained within the pistolgrip 26 of the handle 6, with its nonmoving end 1063 connected to thepieces 59, 60 and a moving end 1064 connected to a downwardly flexed andproximal, retracted end 1067 of a steel band 1066.

A distally-disposed end 1068 of the steel band 1066 is attached to alink coupling 1070 for structural loading, which in turn is attached toa front link 1072 a of a plurality of links 1072 a-1072 d that form alinked rack 1074. Linked rack 1074 is flexible yet has distal links thatform a straight rigid rack assembly that may transfer a significantfiring force through the firing rod 1010 in the shaft 6, yet readilyretract into the pistol grip 26 to minimize the longitudinal length ofthe handle 6. It should be appreciated that the combinationtension/compression spring 1062 increases the amount of firing travelavailable while essentially reducing the minimum length by half over asingle spring.

The firing trigger 20 pivots about a firing trigger pin 96 that isconnected to the handle pieces 59, 60. An upper portion 228 of thefiring trigger 20 moves distally about the firing trigger pin 96 as thefiring trigger 20 is depressed towards pistol grip 26, stretching aproximally placed firing trigger tension spring 222 proximally connectedbetween the upper portion 228 of the firing trigger 20 and the pieces59, 60. The upper portion 228 of the firing trigger 20 engages thelinked rack 1074 during each firing trigger depression by a tractionbiasing mechanism 1078 that also disengages when the firing trigger 20is released. Firing trigger tension spring 222 urges the firing trigger20 distally when released and disengages the traction biasing mechanism1078.

As the linked transmission firing mechanism 1040 actuates, an idler gear1080 is rotated clockwise (as viewed from the left side) by engagementwith a toothed upper surface 1082 of the linked rack 1074. This rotationis coupled to an indicator gear 1084, which thus rotatescounterclockwise in response to the idler gear 1080. Both the idler gear1080 and indicator gear 1084 are rotatably connected to the pieces 59,60 of the handle 6. The gear relationship between the linked rack 1074,idler gear 1080 and indicator gear 1084 may be advantageously selectedso that the toothed upper surface 1082 has tooth dimensions that aresuitably strong and that the indicator gear 1084 makes no more than onerevolution during the full firing travel of the linked transmissionfiring mechanism 1060.

As described in greater detail below, the indicator gear 1084 performsat least four functions. First, when the linked rack 1074 is fullyretracted and both triggers 18, are open as shown in FIG. 42, an opening1086 in a circular ridge 1088 on the left side of the indicator gear1084 is presented to an upper surface 1090 of the locking arm 1048.Locking arm 1048 is biased into the opening 1086 by contact with theclosure trigger 18, which in turn is urged to the open position by aclosure tension spring 1092. Closure trigger tension spring 1092 isconnected proximally to the upper portion 1094 of the closure trigger 18and the handle pieces 59, 60, and thus has energy stored during closingof the closure trigger 18 that urges the closure trigger 18 distally toits unclosed position.

A second function of the indicator gear 1084 is that it is connected tothe indicating retraction knob 1096 externally disposed on the handle 6.Thus, the indicator gear 1084 communicates the relative position of thefiring mechanism 1060 to the indicating retraction knob 1096 so that thesurgeon has a visual indication of how many strokes of the firingtrigger 20 are required to complete firing.

A third function of the indicator gear 1084 is to longitudinally andangularly move an anti-backup release lever 1098 of an anti-backupmechanism (one-way clutch mechanism) 1097 as the surgical stapling andsevering instrument 10 is operated. During the firing strokes, proximalmovement of anti-backup release lever 1098 by indicator gear 1084activates the anti-backup mechanism 1097 that allows distal movement offiring bar 1010 and prevents proximal motion of firing bar 1010. Thismovement also extends the anti-backup release button 1100 from theproximal end of the handle pieces 59, 60 for the operator to actuateshould the need arise for the linked transmission firing mechanism 1060to be retracted during the firing strokes. After completion of thefiring strokes, the indicator gear 1084 reverses direction of rotationas the firing mechanism 1060 retracts. The reversed rotation deactivatesthe anti-backup mechanism 1097, withdraws the anti-backup release button1100 into the handle 6, and rotates the anti-backup release lever 1098laterally to the right to allow continued reverse rotation of theindicator gear 1084.

A fourth function of the indicator gear 1084 is to receive a manualrotation from the indicating retraction knob 1096 (clockwise in thedepiction of FIG. 42) to retract the firing mechanism 1060 withanti-backup mechanism 1097 unlocked, thereby overcoming any binding inthe firing mechanism 1060 that is not readily overcome by thecombination tension/compression spring 1062. This manual retractionassistance may be employed after a partial firing of the firingmechanism 1060 that would otherwise be prevented by the anti-backupmechanism 1097 that withdraws the anti-backup release button 1100 sothat the latter may not laterally move the anti-backup release lever1098.

Continuing with FIGS. 42-43, anti-backup mechanism 1097 consists of theoperator accessible anti-backup release lever 1098 operably coupled atthe proximal end to the anti-backup release button 1100 and at thedistal end to an anti-backup yoke 1102. In particular, a distal end 1099of the anti-backup release lever 1098 is engaged to the anti-backup yoke1102 by an anti-backup yoke pin 1104. The anti-backup yoke 1102 moveslongitudinally to impart a rotation to an anti-backup cam slot tube 1106that is longitudinally constrained by the handle pieces 59, 90 and thatencompasses the firing rod 1010 distally to the connection of the firingrod 1010 to the link coupling 1070 of the linked rack 1074. Theanti-backup yoke 1102 communicates the longitudinal movement from theanti-backup release lever 1098 via a cam slot tube pin 1108 to theanti-backup cam slot tube 1106. That is, longitudinal movement of camslot tube pin 1108 in an angled slot in the anti-backup cam slot tube1106 rotates the anti-backup cam slot tube 1106.

Trapped between a proximal end of the frame 1016 and the anti-backup camslot tube 1106 respectively are an anti-backup compression spring 1110,an anti-backup plate 1112, and an anti-backup cam tube 1114. Asdepicted, proximal movement of the firing rod 1010 causes theanti-backup plate 1112 to pivot top to the rear, presenting an increasedfrictional contact to the firing rod 1010 that resists further proximalmovement of the firing rod 1010.

This anti-backup plate 1112 pivots in a manner similar to that of ascreen door lock that holds open a screen door when the anti-backup camslot tube 1106 is closely spaced to the anti-backup cam tube 1114.Specifically, the anti-backup compression spring 1110 is able to actupon a top surface of the plate 1112 to tip the anti-backup plate 1112to its locked position. Rotation of the anti-backup cam slot tube 1106causes a distal camming movement of the anti-backup cam tube 1114thereby forcing the top of the anti-backup plate 1112 distally,overcoming the force from the anti-backup compression spring 1110, thuspositioning the anti-backup plate 1112 in an untipped (perpendicular),unlocked position that allows proximal retraction of the firing rod1010.

With particular reference to FIG. 43, the traction biasing mechanism1078 is depicted as being composed of a pawl 1116 that has a distallyprojecting narrow tip 1118 and a rightwardly projecting lateral pin 1120at its proximal end that is rotatably inserted through a hole 1076 inthe upper portion 230 of the firing trigger 20. On the right side of thefiring trigger 20 the lateral pin 1120 receives a biasing member,depicted as biasing wheel 1122. As the firing trigger 20 translates foreand aft, the biasing wheel 1122 traverses an arc proximate to the righthalf piece 59 of the handle 6, overrunning at its distal portion oftravel a biasing ramp 1124 integrally formed in the right half piece 59.The biasing wheel 1122 may advantageously be formed from a resilient,frictional material that induces a counterclockwise rotation (whenviewed from the left) into the lateral pin 1120 of the pawl 1116, thustraction biasing the distally projecting narrow tip 1118 downward into aramped central track 1075 of the nearest link 1072 a-d to engage thelinked rack 1074.

As the firing trigger 20 is released, the biasing wheel 1122 thustractionally biases the pawl 1116 in the opposite direction, raising thenarrow tip 1118 from the ramped central track 1075 of the linked rack1074. To ensure disengagement of the tip 1118 under high load conditionsand at nearly full distal travel of the pawl 1116, the right side of thepawl 1116 ramps up onto a proximally and upwardly facing beveled surface1126 on the rightside of the closure yoke 250 to disengage the narrowtip 1118 from the ramped central track 1075. If the firing trigger 20 isreleased at any point other than full travel, the biasing wheel 1122 isused to lift the narrow tip 1118 from the ramped central track 1075.Whereas a biasing wheel 1122 is depicted, it should be appreciated thatthe shape of the biasing member or wheel 1122 is illustrative and may bevaried to accommodate a variety of shapes that use friction or tractionto engage or disengage the firing of the end effector 12.

Various embodiments of the surgical instrument 10 have the capability torecord instrument conditions at one or more times during use. FIG. 44shows a block diagram of a system 2000 for recording conditions of theinstrument 10. It will be appreciated that the system 2000 may beimplemented in embodiments of the instrument 10 having motorized ormotor-assisted firing, for example, as described above with reference toFIGS. 1-40, as well as embodiments of the instrument 10 havingmechanically actuated firing, for example, as described above withreference to FIGS. 41-43.

The system 2000 may include various sensors 2002, 2004, 2006, 2008,2010, 2012 for sensing instrument conditions. The sensors may bepositioned, for example, on or within the instrument 10. In variousembodiments, the sensors may be dedicated sensors that provide outputonly for the system 2000, or may be dual-use sensors that perform otherfunctions with in the instrument 10. For example, sensors 110, 130, 142described above may be configured to also provide output to the system2000.

Directly or indirectly, each sensor provides a signal to the memorydevice 2001, which records the signals as described in more detailbelow. The memory device 2001 may be any kind of device capable ofstoring or recording sensor signals. For example, the memory device 2001may include a microprocessor, an Electrically Erasable Programmable ReadOnly Memory (EEPROM), or any other suitable storage device. The memorydevice 2001 may record the signals provided by the sensors in anysuitable way. For example, in one embodiment, the memory device 2001 mayrecord the signal from a particular sensor when that signal changesstates. In another embodiment, the memory device 2001 may record a stateof the system 2000, e.g., the signals from all of the sensors includedin the system 2000, when the signal from any sensor changes states. Thismay provide a snap-shot of the state of the instrument 10. In variousembodiments, the memory device 2001 and/or sensors may be implemented toinclude 1-WIRE bus products available from DALLAS SEMICONDUCTOR such as,for example, a 1-WIRE EEPROM.

In various embodiments, the memory device 2001 is externally accessible,allowing an outside device, such as a computer, to access the instrumentconditions recorded by the memory device 2001. For example, the memorydevice 2001 may include a data port 2020. The data port 2020 may providethe stored instrument conditions according to any wired or wirelesscommunication protocol in, for example, serial or parallel format. Thememory device 2001 may also include a removable medium 2021 in additionto or instead of the output port 2020. The removable medium 2021 may beany kind of suitable data storage device that can be removed from theinstrument 10. For example, the removable medium 2021 may include anysuitable kind of flash memory, such as a Personal Computer Memory CardInternational Association (PCMCIA) card, a COMPACTFLASH card, aMULTIMEDIA card, a FLASHMEDIA card, etc. The removable medium 2021 mayalso include any suitable kind of disk-based storage including, forexample, a portable hard drive, a compact disk (CD), a digital videodisk (DVD), etc.

The closure trigger sensor 2002 senses a condition of the closuretrigger 18. FIGS. 45 and 46 show an exemplary embodiment of the closuretrigger sensor 2002. In FIGS. 45 and 46, the closure trigger sensor 2002is positioned between the closure trigger 18 and closure pivot pin 252.It will be appreciated that pulling the closure trigger 18 toward thepistol grip 26 causes the closure trigger 18 to exert a force on theclosure pivot pin 252. The sensor 2002 may be sensitive to this force,and generate a signal in response thereto, for example, as describedabove with respect to sensor 110 and FIGS. 10A and 10B. In variousembodiments, the closure trigger sensor 2002 may be a digital sensorthat indicates only whether the closure trigger 18 is actuated or notactuated. In other various embodiments, the closure trigger sensor 2002may be an analog sensor that indicates the force exerted on the closuretrigger 18 and/or the position of the closure trigger 18. If the closuretrigger sensor 2002 is an analog sensor, an analog-to-digital convertermay be logically positioned between the sensor 2002 and the memorydevice 2001. Also, it will be appreciated that the closure triggersensor 2002 may take any suitable form and be placed at any suitablelocation that allows sensing of the condition of the closure trigger.

The anvil closure sensor 2004 may sense whether the anvil 24 is closed.FIG. 47 shows an exemplary anvil closure sensor 2004. The sensor 2004 ispositioned next to, or within the kidney shaped openings 1006 of thestaple channel 22 as shown. As the anvil 24 is closed, anvil pivot pins25 slides through the kidney shaped openings 1006 and into contact withthe sensor 2004, causing the sensor 2004 to generate a signal indicatingthat the anvil 24 is closed. The sensor 2004 may be any suitable kind ofdigital or analog sensor including a proximity sensor, etc. It will beappreciated that when the anvil closure sensor 2004 is an analog sensor,an analog-to-digital converter may be included logically between thesensor 2004 and the memory device 2001.

Anvil closure load sensor 2006 is shown placed on an inside bottomsurface of the staple channel 22. In use, the sensor 2006 may be incontact with a bottom side of the staple cartridge 34 (not shown in FIG.46). As the anvil 24 is closed, it exerts a force on the staplecartridge 34 which is transferred to the sensor 2006. In response, thesensor 2006 generates a signal. The signal may be an analog signalproportional to the force exerted on the sensor 2006 by the staplecartridge 34 and due to the closing of the anvil 24. Referring the FIG.44, the analog signal may be provided to an analog-to-digital converter2014, which converts the analog signal to a digital signal beforeproviding it to the memory device 2001. It will be appreciated thatembodiments where the sensor 2006 is a digital or binary sensor may notinclude analog-to-digital converter 2014.

The firing trigger sensor 110 senses the position and/or state of thefiring trigger 20. In motorized or motor-assisted embodiments of theinstrument, the firing trigger sensor may double as the run motor sensor110 described above. In addition, the firing trigger sensor 110 may takeany of the forms described above, and may be analog or digital. FIGS. 45and 46 show an additional embodiment of the firing trigger sensor 110.In FIGS. 45 and 46, the firing trigger sensor is mounted between firingtrigger 20 and firing trigger pivot pin 96. When firing trigger 20 ispulled, it will exert a force on firing trigger pivot pin 96 that issensed by the sensor 110. Referring to FIG. 44, In embodiments where theoutput of the firing trigger sensor 110 is analog, analog-to-digitalconverter 2016 is included logically between the firing trigger sensor110 and the memory device 2001.

The knife position sensor 2008 senses the position of the knife 32 orcutting surface 1027 within the staple channel 22. FIGS. 47 and 48 showembodiments of a knife position sensor 2008 that are suitable for usewith the mechanically actuated shaft 8 and end effector 12 shown in FIG.41. The sensor 2008 includes a magnet 2009 coupled to the firing bar1022 of the instrument 10. A coil 2011 is positioned around the firingbar 1022, and may be installed; for example, along the longitudinalrecess 1014 of the firing trough member 1012 (see FIG. 41). As the knife32 and cutting surface 1027 are reciprocated through the staple channel22, the firing bar 1022 and magnet 2009 may move back and forth throughthe coil 2011. This motion relative to the coil induces a voltage in thecoil proportional to the position of the firing rod within the coil andthe cutting edge 1027 within the staple channel 22. This voltage may beprovided to the memory device 2001, for example, via analog-to-digitalconverter 2018.

In various embodiments, the knife position sensor 2008 may instead beimplemented as a series of digital sensors (not shown) placed at variouspositions on or within the shaft 8. The digital sensors may sense afeature of the firing bar 1022 such as, for example, magnet 2009, as thefeature reciprocates through the shaft 8. The position of the firing bar1022 within the shaft 8, and by extension, the position of the knife 32within the staple channel 22, may be approximated as the position of thelast digital sensor tripped.

It will be appreciated that the knife position may also be sensed inembodiments of the instrument 10 having a rotary driven end effector 12and shaft 8, for example, as described above, with reference to FIGS.3-6. An encoder, such as encoder 268, may be configured to generate asignal proportional to the rotation of the helical screw shaft 36, orany other drive shaft or gear. Because the rotation of the shaft 36 andother drive shafts and gears is proportional to the movement of theknife 32 through the channel 22, the signal generated by the encoder 268is also proportional to the movement of the knife 32. Thus, the outputof the encoder 268 may be provided to the memory device 2001.

The cartridge present sensor 2010 may sense the presence of the staplecartridge 34 within the staple channel 22. In motorized ormotor-assisted instruments, the cartridge present sensor 2010 may doubleas the cartridge lock-out sensor 136 described above with reference toFIG. 11. FIGS. 50 and 51 show an embodiment of the cartridge presentsensor 2010. In the embodiment shown, the cartridge present sensor 2010includes two contacts, 2011 and 2013. When no cartridge 34 is present,the contacts 2011, 2013 form an open circuit. When a cartridge 34 ispresent, the cartridge tray 1028 of the staple cartridge 34 contacts thecontacts 2011, 2013, a closed circuit is formed. When the circuit isopen, the sensor 2010 may output a logic zero. When the circuit isclosed, the sensor 2010 may output a logic one. The output of the sensor2010 is provided to memory device 2001, as shown in FIG. 44.

The cartridge condition sensor 2012 may indicate whether a cartridge 34installed within the staple channel 22 has been fired or spent. As theknife 32 is translated through the end effector 12, it pushes the sled33, which fires the staple cartridge. Then the knife 32 is translatedback to its original position, leaving the sled 33 at the distal end ofthe cartridge. Without the sled 33 to guide it, the knife 32 may fallinto lock-out pocket 2022. Sensor 2012 may sense whether the knife 32 ispresent in the lock-out pocket 2022, which indirectly indicates whetherthe cartridge 34 has been spent. It will be appreciated that in variousembodiments, sensor 2012 may directly sense the present of the sled atthe proximate end of the cartridge 34, thus eliminating the need for theknife 32 to fall into the lock-out pocket 2022.

FIGS. 52A and 52B depict a process flow 2200 for operating embodimentsof the surgical instrument 10 configured as an endocutter and having thecapability to record instrument conditions according to variousembodiments. At box 2202, the anvil 24 of the instrument 10 may beclosed. This causes the closure trigger sensor 2002 and or the anvilclosure sensor 2006 to change state. In response, the memory device 2001may record the state of all of the sensors in the system 2000 at box2203. At box 2204, the instrument 10 may be inserted into a patient.When the instrument is inserted, the anvil 24 may be opened and closedat box 2206, for example, to manipulate tissue at the surgical site.Each opening and closing of the anvil 24 causes the closure triggersensor 2002 and/or the anvil closure sensor 2004 to change state. Inresponse, the memory device 2001 records the state of the system 2000 atbox 2205.

At box 2208, tissue is clamped for cutting and stapling. If the anvil 24is not closed at decision block 2210, continued clamping is required. Ifthe anvil 24 is closed, then the sensors 2002, 2004 and/or 2006 maychange state, prompting the memory device 2001 to record the state ofthe system at box 2213. This recording may include a closure pressurereceived from sensor 2006. At box 2212, cutting and stapling may occur.Firing trigger sensor 110 may change state as the firing trigger 20 ispulled toward the pistol grip 26. Also, as the knife 32 moves throughthe staple channel 22, knife position sensor 2008 will change state. Inresponse, the memory device 2001 may record the state of the system 2000at box 2013.

When the cutting and stapling operations are complete, the knife 32 mayreturn to a pre-firing position. Because the cartridge 34 has now beenfired, the knife 32 may fall into lock-out pocket 2022, changing thestate of cartridge condition sensor 2012 and triggering the memorydevice 2001 to record the state of the system 2000 at box 2015. Theanvil 24 may then be opened to clear the tissue. This may cause one ormore of the closure trigger sensor 2002, anvil closure sensor 2004 andanvil closure load sensor 2006 to change state, resulting in arecordation of the state of the system 2000 at box 2017. After thetissue is cleared, the anvil 24 may be again closed at box 2220. Thiscauses another state change for at least sensors 2002 and 2004, which inturn causes the memory device 2001 to record the state of the system atbox 2019. Then the instrument 10 may be removed from the patient at box2222.

If the instrument 10 is to be used again during the same procedure, theanvil may be opened at box 2224, triggering another recordation of thesystem state at box 2223. The spent cartridge 34 may be removed from theend effector 12 at box 2226. This causes cartridge present sensor 2010to change state and cause a recordation of the system state at box 2225.Another cartridge 34 may be inserted at box 2228. This causes a statechange in the cartridge present sensor 2010 and a recordation of thesystem state at box 2227. If the other cartridge 34 is a new cartridge,indicated at decision block 2230, its insertion may also cause a statechange to cartridge condition sensor 2012. In that case, the systemstate may be recorded at box 2231.

FIG. 53 shows an exemplary memory map 2300 from the memory device 2001according to various embodiments. The memory map 2300 includes a seriesof columns 2302, 2304, 2306, 2308, 2310, 2312, 2314, 2316 and rows (notlabeled). Column 2302 shows an event number for each of the rows. Theother columns represent the output of one sensor of the system 2000. Allof the sensor readings recorded at a given time may be recorded in thesame row under the same event number. Hence, each row represents aninstance where one or more of the signals from the sensors of the system2000 are recorded.

Column 2304 lists the closure load recorded at each event. This mayreflect the output of anvil closure load sensor 2006. Column 2306 liststhe firing stroke position. This may be derived from the knife positionsensor 2008. For example, the total travel of the knife 32 may bedivided into partitions. The number listed in column 2306 may representthe partition where the knife 32 is currently present. The firing loadis listed in column 2308. This may be derived from the firing triggersensor 110. The knife position is listed at column 2310. The knifeposition may be derived from the knife position sensor 2008 similar tothe firing stroke. Whether the anvil 24 is open or closed may be listedat column 2312. This value may be derived from the output of the anvilclosure sensor 2004 and/or the anvil closure load sensor 2006. Whetherthe sled 33 is present, or whether the cartridge 34 is spent, may beindicated at column 2314. This value may be derived from the cartridgecondition sensor 2012. Finally, whether the cartridge 34 is present maybe indicated a column 2316. This value may be derived from cartridgepresent sensor 2010. It will be appreciated that various other valuesmay be stored at memory device 2001 including, for example, the end andbeginning of firing strokes, for example, as measured by sensors 130,142.

While the present invention has been illustrated by description ofseveral embodiments and while the illustrative embodiments have beendescribed in considerable detail, it is not the intention of theapplicant to restrict or in any way limit the scope of the appendedclaims to such detail. Additional advantages and modifications mayreadily appear to those skilled in the art.

For example, although the embodiments described above have advantagesfor an endoscopically employed surgical severing and stapling instrument100, a similar embodiments may be used in other clinical procedures. Itis generally accepted that endoscopic procedures are more common thanlaparoscopic procedures. Accordingly, the present invention has beendiscussed in terms of endoscopic procedures and apparatus. However, useherein of terms such as “endoscopic”, should not be construed to limitthe present invention to a surgical instrument for use only inconjunction with an endoscopic tube (i.e., trocar). On the contrary, itis believed that the present invention may find use in any procedurewhere access is limited to a small incision, including but not limitedto laparoscopic procedures, as well as open procedures.

Any patent, publication, or information, in whole or in part, that issaid to be incorporated by reference herein is incorporated herein onlyto the extent that the incorporated material does not conflict withexisting definitions, statements, or other disclosure material set forthin this document. As such the disclosure as explicitly set forth hereinsupersedes any conflicting material incorporated herein by reference.

What is claimed is:
 1. A surgical instrument, comprising: a handle; ashaft, comprising: a proximal portion extending from said handle; and adistal portion; a firing member; a motor, wherein said motor isconfigured to be operated in a first direction to advance said firingmember toward said distal portion during a firing stroke, wherein saidfiring stroke comprises a firing stroke end, wherein said motor isconfigured to be operated in a second direction to retract said firingmember away from said distal portion; and a switch configured to detectwhen said firing member has reached said firing stroke end, wherein saidmotor is configured to be automatically operated in said seconddirection when said switch detects said firing stroke end.
 2. Thesurgical instrument of claim 1, further comprising a firing triggerconfigured to operate said motor when said firing trigger is actuated.3. The surgical instrument of claim 1, further comprising: a battery;and a firing trigger configured to place said battery in electricalcommunication with said motor when said firing trigger is actuated. 4.The surgical instrument of claim 1, wherein said switch is configurablein a first state and a second state, wherein a first polarity can beapplied to said motor when said switch is in said first state, andwherein a second polarity can be applied to said motor when said switchis in said second state.
 5. The surgical instrument of claim 1, furthercomprising an end effector extending from said shaft.
 6. The surgicalinstrument of claim 1, further comprising a staple cartridge.
 7. Asurgical instrument, comprising: a handle; a shaft, comprising: aproximal portion extending from said handle; and a distal portion; afiring member; a motor, wherein said motor is configured to be operatedin a first direction to advance said firing member toward said distalend during a firing stroke, wherein said firing stroke comprises afiring stroke end, wherein said motor is configured to be operated in asecond direction to retract said firing member away from said distalend; and means for automatically operating said motor in said seconddirection after said firing member reaches said firing stroke end. 8.The surgical instrument of claim 7, further comprising a firing triggerconfigured to operate said motor when said firing trigger is actuated.9. The surgical instrument of claim 7, further comprising: a battery;and a firing trigger configured to place said battery in electricalcommunication with said motor when said firing trigger is actuated. 10.The surgical instrument of claim 7, wherein said means comprises aswitch.
 11. The surgical instrument of claim 10, wherein said switch isconfigurable in a first state and a second state, wherein a firstpolarity can be applied to said motor when said switch is in said firststate, and wherein a second polarity can be applied to said motor whensaid switch is in said second state.
 12. The surgical instrument ofclaim 7, further comprising an end effector extending from said shaft.13. The surgical instrument of claim 7, further comprising a staplecartridge.
 14. A surgical instrument system, comprising: a handle; anend effector comprising a distal end; a firing member; a motor, whereinsaid motor is configured to be operated in a first direction to advancesaid firing member toward said distal end during a firing stroke,wherein said firing stroke comprises a firing stroke end, wherein saidmotor is configured to be operated in a second direction to retract saidfiring member away from said distal end; a sensor configured to sense acondition when said firing member is reaching said firing stroke end;and a controller configured to automatically operate said motor in saidsecond direction when said sensor senses said condition.
 15. Thesurgical instrument system of claim 14, further comprising a firingtrigger configured to operate said motor when said firing trigger isactuated.
 16. The surgical instrument system of claim 14, furthercomprising: a battery; and a firing trigger configured to place saidbattery in electrical communication with said motor when said firingtrigger is actuated.
 17. The surgical instrument system of claim 14,wherein said sensor comprises a switch.
 18. The surgical instrumentsystem of claim 17, wherein said switch is configurable in a first stateand a second state, wherein said controller is configured to apply afirst polarity to said motor when said switch is in said first state,and wherein said controller is configured to apply a second polarity tosaid motor when said switch is in said second state.
 19. The surgicalinstrument system of claim 14, further comprising an end effectorextending from said shaft.
 20. The surgical instrument system of claim14, further comprising a staple cartridge.
 21. A surgical instrumentsystem, comprising: a handle; an end effector comprising a distal end; afiring member; a motor, wherein said motor is configured to be operatedin a first direction to advance said firing member toward said distalend during a firing stroke, wherein said firing stroke comprises afiring stroke end, wherein said motor is configured to be operated in asecond direction to retract said firing member away from said distalend; a sensor configured to sense a condition when said firing memberhas reached said firing stroke end; and means for applying a firstpolarity to said motor prior to said sensor detecting said firing strokeend and for applying a polarity to said motor after sensor detects saidfiring stroke end.